1. Field of the Invention
The present invention belongs to a technical field of female terminals to be fitted in a housing of a female connector, and relates to improvement of a female terminal, which has a leaf spring for contacting a male terminal, said leaf spring being provided inside a tubular body thereof.
2. Related Art
A female terminal is known, which comprises a tubular body into which a male terminal is inserted through a front opening thereof and a leaf spring being provided inside the body. In the case of the female terminal that is disclosed by Japanese Patent unexamined publication gazette Heisei 9-147950, the body has a bottom wall, side walls that are provided on both ends of the bottom wall in its width direction to oppose to each other, and upper walls that are provided on the side walls on their upper side to oppose to the bottom wall. The leaf spring has a first bent part that is integrally provided on the front end of the bottom wall of the body and bends upward and rearward, an intermediate part that extends rearward from the first bent part, a second bent part that bends downward and forward from the rear end of the intermediate part, and a top end part that extends forward from the second bent part, keeps itself away from the intermediate part and contacts the bottom wall of the body by the front end thereof. Furthermore, this female terminal has a first rising piece that rises from the bottom wall of the body and a second rising piece that rises from the front end of the top end part of the leaf spring. In the case of this female terminal, when a male terminal is inserted through the front opening of the body into a regular position, the front end of the top end part will contact the bottom wall, and the leaf spring will exhibit its elastic restoring force for an elastic range between the front end of the top end part and the first bent part to generate an adequate contact force between itself and the male terminal. If the male terminal is inserted with a slight tilt away from the regular position, the leaf spring will be subjected to a prying force or the like, and the entirety of the top end part thereof will contact the bottom wall. As a result, of the leaf spring, only the intermediate part will function as an elastic range, and the leaf spring will show a higher rigidity, preventing its excessive deformation. If the prying force or the like gets greater, the intermediate part will come into contact with the first rising piece and the second rising piece successively, and the leaf spring will be prevented from further excessive deformation.
When a female terminal is to be fitted into a housing, a cell of the housing is provided with a flexible piece having flexibility, and this flexible piece will be fitted onto the female terminal. There are two modes for this fitting. In a first mode, a flexible piece is made to fit into a flexible-piece-receiving hole that is opened in the bottom wall of the female terminal. In the second mode, a flexible piece is fitted onto the rear end of the upper wall of the body. In the case of the female terminal described above, the first mode wherein a flexible-piece-receiving hole is opened in the bottom wall can not be adopted and the second mode must be adopted, because the top end part of the leaf spring must be supported by the bottom wall and a part from which the first rising piece is to be cut and raised must be secured in the bottom wall. This, however, makes it inevitable that when the flexible piece is to be disengaged from the female terminal by means of a precision screwdriver or the like, one has to lift the flexible piece by inserting the precision screwdriver or the like deep into the cell. This work can not be done under visual observation. One has to rely on his or her hunch, and the workablility is very low.
The present invention was made in view of the above-mentioned points, and one objective of the invention is to secure an adequate contact force between the leaf spring and a male terminal, prevent excessive deformation of the leaf spring, make it possible to open a flexible-piece-receiving hole in the bottom wall and improve the workability of the work of disengaging a flexible piece from the female terminal, by fitting the front end of the top end part and the intermediate part of the leaf spring onto the side walls.
To accomplish the above-mentioned objective, the female terminal of the present invention comprises a tubular body having a bottom wall, side walls provided on both ends of the bottom wall in the width direction to oppose to each other and an upper wall provided on the upper side of the side wall to oppose to the bottom wall, into which a male terminal is inserted through a front opening thereof, a leaf spring being provided inside the body and having a first bent part being integrally provided on the front end of the bottom wall of the body and being bent upward and rearward, an intermediate part extending rearward from the first bent part, a second bent part being bent downward and forward from the rear end of the intermediate part, and a top end part extending forward from the second bent part and keeping itself away from the intermediate part, a first fitting means for fitting the front end of the top end part of the leaf spring onto the side walls, a second fitting means, which allows, when the intermediate part of the leaf spring is displaced downward to contact the top end part of the leaf spring, a part ahead of said contacting part of the intermediate part of the leaf spring to be displaced downward by a certain length, and fits the part onto the side walls at the bottom dead point, and a flexible-piece-receiving hole being opened in the bottom wall ahead of a part at which the second bent part or the rear end of the top end part of the leaf spring being displaced downward contacts the bottom wall.
In the case of this female terminal, when it is inserted into a cell of a housing, a flexible piece will fit into the flexible-piece-receiving hole to fit the female terminal in the housing. If a male terminal is inserted through the front opening of the body, as the front end of the top end part of the leaf spring is fitted onto the side walls by the first fitting means, when the male terminal is inserted between the upper wall and the leaf spring and comes to the regular position, the leaf spring will exhibit its elastic restoring force for its elastic range between the front end of the top end part and the first bent part to provide an appropriate contact force between the male terminal and the leaf spring. If a prying force or the like acts, the second bent part of the leaf spring or the rear end of the top end part thereof will be displaced downward to contact the bottom wall, and in turn, the leaf spring will exhibit an elastic restoring force for an elastic range of only the intermediate part to balance the prying force or the like and prevent the leaf spring from excessive deformation. If the prying force or the like gets greater, the intermediate part of the leaf spring will be displaced downward to contact the top end part of the leaf spring, and in turn, the prying force or the like will be balanced by this contact and the leaf spring will be prevented from excessive deformation. If the prying force or the like increases much more, a part of the intermediate part ahead of the above-mentioned contact part of the intermediate part of the leaf spring will be displaced downward, and it will be stopped at a bottom dead point and fitted onto the side walls by the second fitting means. The prying force or the like will be balanced by this and the leaf spring will be prevented from excessive deformation. In this way, the prying force or the like is balanced in three stages to prevent the leaf spring from being deformed excessively.
In this case, as the front end of the top end part of the leaf spring is fitted onto the side walls by the first fitting means, the part of the leaf spring to contact the bottom wall is the second bent part or the rear end of the top end part, in other words, a part around the rear end of the leaf spring. Moreover, as the intermediate part of the leaf spring is fitted onto the side walls by the second fitting means, a rising piece that was explained in the related art is not needed, and in turn, there is no need of securing a part, in the bottom wall, from which the rising piece is cut and raised. With these arrangements, a flexible-piece-receiving hole can be opened in the bottom wall between the first bent part of the leaf spring and the part the second bent part or the rear end of the top end part of the leaf spring contacts when it is displaced downward. As a result of this, the operation of disengaging the flexible piece from the female terminal can be done near the front end of the body. As the operation can be done under visual observation, the workability is improved. Moreover, as there is a space beneath the intermediate part of the leaf spring between the first bent part and the front end of the top end part, the height of the female terminal can be kept low by accommodating the flexible piece in this space. As a result, the female terminal can be compactified. Moreover, costs can be reduced through common use of metal molds for this female terminal and a female terminal without any flexible-piece-receiving hole made in the bottom wall thereof. Further, the elimination of the conventional rising pieces results in a more compact development of the female terminal, reduced number of bending processes, a reduced course of production, and improved precision of working.
To sum up, in the female terminal of the present invention the front end of the top end part of the leaf spring and a part of the intermediate part of the leaf spring ahead of the contact part of the intermediate part are fitted onto the side walls. As a result, the female terminal of the present invention provides an appropriate contact force between itself and a male terminal, prevents the leaf spring from being deformed excessively, enables opening a flexible-piece-receiving hole in the bottom wall, and in turn, allows operation of disengaging the flexible piece from the female terminal near the front end of the body, enables the operation under visual observation, and enhances the workability. Moreover, as the flexible piece can be accommodated in a space beneath the intermediate part of the leaf spring between the first bent part and the front end of the top end part, the female terminal can be compactified. Furthermore, through the common use of metal molds with a female terminal having no flexible-piece-receiving hole in the bottom wall, the costs can be reduced. Elimination of the conventional rising pieces results in a more compact development of the female terminal, a reduced number of bending processes, a shorter production process, and an improved accuracy of working.